A Benzothiadiazole-based Covalent organic framework for highly efficiant visible light mediated hetrerogeneous photocatalysis

Abstract

In recent years, the synthesis and design of porous organic materials have gained huge interest because of their extraordinary properties such as very high BET surface area, high chemical and thermal stability, low density, and inherent properties of building units. These porous organic materials are constructed by purely organic building units connected via strong covalent bonds to form an ordered framework. Covalent organic frameworks (COFs) are a kind of porous organic material that exhibits crystallinity and porosity. These fully conjugated materials show exceptional applications in biological medicine, sensing, gas adsorption and separation, optoelectronics, and catalysis. In general, COFs' diverse uses are due to their versatile molecular design and synthetic techniques, broad conjugated degrees, band structure, heteroatoms, and porous features. The motive of the study is to synthesize a benzothiadiazole-based COF to reduce the band gap between the valence band (VB) and conduction band (CB) of the resultant framework. A crystalline benzothiadiazole-based (TAPT-BTD-COF) was synthesized by the Schiff-based condensation reaction between the monomers TAPT and BTD-CHO. Furthermore, TAPT-BTD-COF was used as a heterogeneous catalyst for the oxidative coupling reaction between o-phenylenediamine and aromatic aldehydes under visible-light conditions with excellent yield. The first chapter of the thesis deals with a brief introduction, design, and applications of COFs. The second chapter contains the synthetic schemes, experimental procedures, and basic characterizations of TAPT-BTD-COF.